MSK 1 - Skeletal System Flashcards
What are the main functions of the skeletal system?
Support structure and movement, protect internal organs, produce blood cells, store triglycerides, store and release minerals
Give examples of cavities protected by the skeletal system
Cranial, thoracic, abdominal, pelvic, gastrointestinal tract
What types of blood cells are produced in bone and where / from what are they made?
Red and white blood cells; within red bone marrow; from hematopoietic stem cells
What triglycerides are stored in bone and where exactly are they stored?
Adipocytes (fat cells); yellow bone marrow within the medullary cavity of long bones
What minerals are stored in bone and where exactly are they stored?
Calcium and phosphate; within the extracellular matrix of bone
What are the two main divisions of the skeleton
Axial and appendicular
What is the function of the axial skeleton
Encloses and protects body cavities
Where / what is the axial skeleton
Head and trunk
What is the function of the appendicular skeleton
Supports movement and locomotion
Where / what is the appendicular skeleton
Upper and lower limbs
What are the three structural parts of bone
Spongey, compact, medullary cavity
What is spongey bone
Internal porous layer of bone
What is compact bone
External dense layer of bone
What is the medullary cavity
Hollow space in bone
What are the 5 types of bone?
Long, short, sesamoid, flat, irregular
Describe the general shape of long bones
Long, skinny shaft with knobs at either end
Where are long bones found
Limbs
What are the three regions of a long bone
Epiphyses, metaphyses, diaphysis
What is an epiphysis
Extreme ends of long bones
What is a metaphysis
Transitional zone between epiphyses and diaphyses of long bone
What is a diaphysis
Shaft of long bone containing medullary cavity
Give examples of long bones
Clavical, humerus, radius, ulna, metacarpals, phalanges
Femur, tibia, fibula, metatarsals, phalanges
Describe the general shape of short bones
Small, square shaped, length=width
Where are short bones found
Wrists and ankles
Give examples of short bones
Carpals, tarsals
Where are sesamoid bones found
Develop in tendons were friction is excessive
Give examples of sesamoid bones
Pisiform, patella
Describe the general shape of flat bones
Thin, broad, plate like structure
What is the general purpose of flat bones
Surround and protect body cavities
Give examples of flat bones
Skull cap (calvaria), scapulae, ribs, sternum, pelvic girdle
What are irregular bones
Bones which shape does not group with any other category
Give examples of irregular bones
Bones of face, vertebrae, sacrum
Flat bones make up the axial / appendicular / both skeleton?
Both
Irregular bones make up the axial / appendicular / both skeleton?
Axial
Long bones make up the axial / appendicular / both skeleton?
Appendicular
Sesamoid bones make up the axial / appendicular / both skeleton?
Appendicular (more friction in limbs)
Short bones make up the axial / appendicular / both skeleton?
Appendicular
Is bone dynamic or stagnant
Dynamic
What type of tissue is bone
Dense connective
What is the general makeup of bone tissue
Osseous cells suspended in a dense extracellular matrix
What are the two components of the extracellular matrix of bone tissue
Bone minerals, organic matrix
What percent of bone weight are bone minerals, organic matrix, and water
Minerals = 55%
Organic matrix = 30%
Water = 15%
What gives bone its characteristic hard structure
Bone minerals
Describe the composition of bone minerals
Mix of calcium salts (calcium, phosphate) combine to form hydroxyapatite, a mega crystal structure (hard)
What gives bone its flexibility
Organic matrix
Describe the composition of the organic matrix of bone tissue
Collagen fibers + ground substance + water forms the organic matrix
What property does the combination of bone minerals and organic matrix create
Tensile strength
Describe the transition between osteoprogenitor cells, osteoblasts, and osteocytes
Osteoprogenitor cells are capable of division and differentiate into osteoblasta which get trapped in the mineralized ECM and transition into osteocytes
What is the function of osteoprogentitor cells
Stem cells of bone; divide
What is the function of osteoblasts
Build up Bone; secrete organic bone matrix and begin calcification of bone matrix
What is the function of osteocytes
Mature bone cells that maintain daily metabolism, detect forces on bone
Describe the formation of osteoclasts
Monocytes (large cells from red bone marrow) fuse to form large multinucleated osteoclasts
What is the function of osteoclasts
Consume bone; when ruffled edge contacts bone, releases powerful lysosomal enzymes and acids
What is hydroxyapatite
Mineralized bone
What is the periosteum
External fibrous connective tissue layer that surrounds the compact bone
Where does the periosteum surround
All surfaces of bone / compact bone except articular surfaces
What is the endosteum
Connective tissue layer that lines the medullary cavity / spongey bone
Where is spongey bone found
At the ends of bone and lining the medullary cavity
How is spongey bone oriented
Along lines of stress / areas of tension and compression
Is spongey bone strong in bending or compression
Compression
Is compact bone strong in bending or compression
Bending
How is compact bone oriented
Longitudinally
Trabecular and cancellous bone are synonyms for
Spongey bone
Cortical and dense bone are synonyms for
Compact bone
What is a trabeculae a unit of
Spongy bone
What is an osteon a unit of
Compact bone
What are lamellae
Mineralized circular plates of bone matrix
Describe the concentric directional organization of concentric lamellae and its purpose
Alternating directions for concentric lamellae which gives more strength
What are interstitial lamellae
Broken down fragments of osteons in between osteons
What are concentric lamellae
Layers in an osteon
What are circumferential lamellae
Large plates that completely surround the external and internal circumferences of compact bone
Describe the pathway of nutrient vasculature
Nutrient artery enters at diaphysis and branches up and down the bone. Travels within the medullary capillary.
Describe the pathways of central canal capillaries
Travel up and down through center of osteons
Describe the pathway of periosteal vasculature
Runs superficially in periosteum
What are interosteonic canals and what is their purpose
Vascular communication between osteons and many sources of blood. Run horizontally into bone
What areas on bone receive sensory innervation? Somatic sensory innervation?
Sensory nerves reach all aspects of bone just by following vasculature. Periosteum is only area that receives somatic innervation
What is the purpose of sensory fibers within bone
Aid regulation of bone homeostasis and growth
Where is bone marrow found
In hollow portions on bone such as areas of excess spongy bone or within the medullary cavity of a long bone
What is the purpose of red bone marrow
Supports red and white blood cell formation and filters out out blood cells
What is the purpose of yellow bone marrow
Supports the vasculature within the medullary cavity and stores triglycerides
Where are osteocytes located (3 answers)
Between concentric lamellae, within compact bone, within spongy bone
